This invention relates to printed circuit connectors and, more particularly, to flexible jumper strips.
In the construction of electrical assemblies, sub-systems made on hard or flexible printed circuits are often used. These sub-systems then have to be connected together with jumper cables or strips. Typically, the jumper strips are made in the form of a plurality of parallel conductors encased between insulating layers with terminating pins at the ends of each lead extending beyond the insulation. Such a jumper strip is shown in U.S. Pat. No. 3,221,286 issued to G. A. Fedde.
Most of the prior art jumper strips are either not flexible or they tend to flex or bend in the wrong areas. The weakest point is often where the pins enter the insulation. This results in a sharp crease or bend which can eventually lead to the breaking of the pin. Also, the flexing of such jumpers results in a separation of the insulating layers from the conductor. To overcome these problems, a flexible jumper made by encasing a conductor pattern between two insulating sheets and imparting a V-shape to the pins is disclosed in U.S. Pat. No. 4,064,622 filed Apr. 30, 1976 to Gilbert Morris, et al. and assigned to the assignee of the present invention. While the Morris et al. jumper strip does overcome many of the problems inherent in the prior art, nevertheless, it suffers from deficiencies of its own. In particular, a mechanical force is applied to the pins in order to impart the V-shape. This may eventually result in the breakdown of the pins themselves.
In the connector described in U.S. Pat. No. 3,997,229 to Narozny et al. the strength of a jumper strip at the transition from the insulation to the termination pins is increased by soldering individual stiffening rods to the pins. However, this is a costly and time consuming process.